The investigation into the smuggling network has been ongoing for a number of months and has been carried out by the Garda National Immigration Bureau.

A spokesperson for the Dublin Airport Authority said it has been in touch with the Garda National Immigration Bureau, and is assisting gardaí with their inquiries.

Breaches

Meanwhile, Minister for Justice Frances Fitzgerald has welcomed the arrests.

"What's important is that it is fully investigated and any breaches, if there are breaches, are examined fully and that we get to the facts in relation to this.

"I welcome the work of An Garda Siochana in dealing with this issue but, as I say, this is an international issue. We work on this day-in, day-out in relation to our borders and our airports.

"It's very early in the investigation. Let's see what facts emerge. Let's see what the lessons are from this. There's a full garda investigation underway and we have to wait the outcome of that to see where the facts lead us," she said.

Asked if what was uncovered has done Ireland reputations damage, she said "No, we are working very closely with all member states, with the UK. We've had some huge successes in relation, for example, to sham marriages in recent years, in relation to illegal entry to this country.

"There's ongoing liaison between An Garda Siochana and the PSNI and some very strong successes.

"The lesson would appear to be, and this is very early stage, the investigation has to take place and it is one of ongoing vigilance and accountability and very high focus on security and immigration in this country.

"We now have advanced passenger information sharing with the UK. We have a huge amount of contact with Interpol and Europol and I'm very confident that with the new arrangements now in place that database information is being shared more effectively than ever but extreme vigilance is needed on an ongoing basis at Dublin Airport and every point of entry into the country," she added.

Garda Commissioner Noirin O'Sullivan, asked to comment on the arrests at Dublin Airport, said "It is a live investigation and we are at a very early stage of the investigation and it is difficult to make a detailed comment at this stage.

"However, what our focus is on is working with our colleagues in the immigration service and with colleagues at our ports and borders to make sure we strengthen our border controls and this is part of that," she said.

Assistant Garda Commissioner John O'Driscoll, who is in charge of Special Crime Operations, told a press conference that gardaí intensified their investigation during recent changes at Dublin Airport.

"We have had the cooperation of a number of agencies, in recent times there has been a reconfiguration of personnel working the immigration control at Dublin airport which has involved an input of civilian staff attached to Irish Naturalisation and Immigration control booths," Assistant Garda Commissioner John O'Driscoll.

"This has offered the opportunity for An Garda Siochana to enhance its investigative role and through combined efforts of Irish Naturalisation and Immigration Service providing the information which it gleans through immigration control to An Garda Siochana, that we discover any weaknesses in the system."

He continued; "This comprehensive gathering of information and analysing has brought us to the situation were we have arrested three people today, two of whom are employees of a carrier of passengers.

"One person is a potential illegal immigrant who illegally entered the state who was facilitated by our two suspects.

"There is always the danger that employees- and this is world wide - who have the capacity to facilitate illegal immigration will do certain acts that may assist in that regard."